CN102728592B - Exhaust device with deflection plate - Google Patents

Abstract

The invention relates to an exhaust device with a deflection plate, which comprises an operation cabinet, wherein an accommodating space is formed in the operation cabinet, an opening is formed in the front of the operation cabinet, a long and narrow air suction opening with an opening facing downwards and parallel to a rear plate is arranged at the bottom of an air suction cover at the top end of the operation cabinet, a left deflection plate is vertically fixed in the accommodating space in a manner of deflecting relative to a left side plate, a right deflection plate is symmetrical to the left deflection plate, and the right deflection plate is vertically fixed in the accommodating space in a manner of deflecting relative to a right side plate. Therefore, when the narrow and long air extraction opening extracts air upwards, air can enter the operation cabinet by virtue of the guidance of the left deflection plate and the right deflection plate, and pollutants are prevented from being leaked outwards from the opening in front of the operation cabinet.

Description

Exhaust with deflector

technical field

The invention relates to an exhaust device with a deflecting plate, especially a deflecting plate that can guide the airflow in the operation cabinet to prevent the leakage of pollutants, and is suitable for exhaust cabinets in factories and laboratories and commercial Exhaust unit with deflector for kitchen hoods. the

Background technique

In the prior art, the air extraction method of the traditional exhaust cabinet is to set up an opening shutter at the upper end of the gas cabinet, and erect a deflector with a specially designed opening at the rear of the cabinet body, and discharge the air in the cabinet through the exhaust device and the duct. Harmful gas is extracted through the opening of the upper shutter and the opening of the deflector at the rear of the cabinet. When using the exhaust cabinet, the suction device must be running to perform the pumping action. At this time, the door of the gas cabinet cannot be completely closed or an air inlet must be reserved under the door sill to prevent the suction device from being damaged due to the inability to supply air. Motor idling or even burnt. And when in use, the door of the gas cabinet also often needs to be opened to an appropriate height, so that the operator can stretch his hand into the cabinet for experimental operation. However, when the door of the traditional exhaust cabinet is opened, the harmful substances in the cabinet can easily leak from the periphery of the cabinet door due to the basic reasons of aerodynamics, and when the operator opens and closes the cabinet door, stands open Leakage is particularly serious when operating experiments in front of the cabinet, and when there are disturbing airflow or people moving around. The main reason for the leakage is that vortices and strong turbulence are easily formed around the cabinet door and the operator's chest, resulting in the exchange of mass and momentum inside and outside the cabinet, so the leakage of pollutants in the cabinet is almost inevitable. Unfortunately, there are very few exhaust cabinets that do not need to have a door switch action, and the operator must stand in front of the open cabinet to operate the experiment, and very few exhaust cabinets are placed in a place where there is no surrounding interference airflow and In an environment without people moving around. Therefore, laboratories, factories, and buildings using traditional exhaust cabinets usually smell the sour smell of chemicals, which is actually caused by the continuous leakage of pollutants from the cabinet. Users and those around them often take it for granted, which leads to long-term chemical pollution. the

Therefore, as shown in Figure 13 and 14, the relatively inclined double air curtain type exhaust cabinet of China Taiwan Announcement No. M375855 mainly utilizes oblique air curtains to solve the problem of leakage of the above-mentioned traditional exhaust cabinet. An opening is formed on the front and rear sides of the operation cabinet a, and an air blowing end (b, b1) is respectively provided on the front and rear sides of the bottom plate of the operation cabinet a, and two air blowing ends (b, b1) b1) Air jets are sprayed upwards in inclined and opposite directions, and a suction hood c is provided in the space above the bottom plate, and the suction hood c is provided with a suction end c1, which is connected to two blowing ends (b, b1) are parallel, and the suction end c1 is located between the two blowing ends (b, b1) directly above. In this way, air is pumped at the air suction end c1, and when the two air blowing ends (b, b1) blow air, two oblique air curtains (d, d1) flowing from bottom to top are formed to eliminate the air that is surrounded by two Contaminants between diagonal air curtains. the

The structure of the above-mentioned double air curtain type exhaust cabinet, in addition to the front and rear ends of the operation cabinet forming an open space for the operator to operate, the left and right sides of the operation cabinet are closed facades to block the leakage of harmful gases . In actual use, the two ends of the long and narrow air blowing end (b, b1) must respectively keep a certain gap (f, f1) with the left and right side plates (e, e1) for the purpose of replenishing air. However, the left and right side panels (e, e1) are all closed facades, when the air enters from the gap between the two ends of the air blowing end (b, b1) and the left and right side panels (e, e1) respectively Finally, according to the experimental results, an unstable vortex will be generated in the cabinet, so that part of the air flow will flow out through the above two gaps, and the harmful gas leakage cannot be completely blocked. the

In view of this, in order to improve the above-mentioned shortcomings, so that the exhaust device with deflection plate can effectively reduce the dissipation of pollutants, so as to ensure the safety of use, the inventor has accumulated many years of experience and continuous research and development, and then the present invention is produced. . the

Contents of the invention

The main purpose of the present invention is to provide an exhaust device with a deflector, by means of a narrow and long air suction port at the bottom of the suction hood, and left and right deflectors in the accommodation space below the operation cabinet The unique structure can effectively remove high-temperature oily fume and prevent oily fume from leaking. the

The secondary purpose of the present invention is to provide a kind of exhaust device with deflection plate, by means of the front side of the bottom plate of the operation cabinet is provided with a narrow and long air blowing end, and on the first, left and right sides of the narrow and long air blowing end The structure of the left and right deflection plates in the second air supply space can effectively block the air flow in the operation cabinet to prevent the leakage of pollutants. the

Another object of the present invention is to provide an exhaust device with a deflection plate, by means of a structure in which a deflector is provided at the front end of the left and right side panels of the operation cabinet, and a guide portion is provided at the bottom of the front panel , allowing air to enter the operation cabinet smoothly, and reducing the size of the return area to reduce the chance of pollutant leakage. the

In order to achieve the purpose of the above invention, the exhaust device with deflecting plate provided in the present invention includes an operation cabinet, a left deflecting plate and a right deflecting plate. Among them, the operation cabinet includes a suction hood, a bottom plate, a left side panel, a right side panel and a rear panel, and a frame is formed to form an accommodation space, an opening is formed in front of the operation cabinet, and the bottom of the suction hood is provided with a suction end. The air suction end is formed with a narrow and long air suction port with the opening facing downwards. The long and narrow air suction port is parallel to the rear plate, and the air suction end is connected to the air suction device to draw air upwards; The way is upright and fixed in the accommodation space, so that a first angle is formed between the left deflecting plate and the left side plate; and the right deflecting plate is symmetrical to the left deflecting plate, and the right deflecting plate is opposite to the right side The board is vertically fixed in the accommodating space in a deflected manner, so that a second included angle is formed between the right deflecting board and the right side board, thereby guiding the airflow in the operation cabinet and preventing leakage. the

During implementation, the front end of the left deflecting plate is close to the right side of the left side plate, the front end of the right deflecting plate is close to the left side of the right side plate, and the difference between the first included angle and the second included angle The angled opening faces the rear panel. the

During implementation, the bottom of the front end of the suction hood is provided with an arc-shaped first guide portion, and the top of the front end of the bottom plate is provided with an arc-shaped second guide portion. In addition, the front end of the left panel of the operation cabinet is provided with an arc-shaped first deflector, and the front end of the right panel of the operation cabinet is provided with an arc-shaped second deflector for guiding the airflow into the accommodating space. the

During implementation, the front side of the bottom plate is provided with a long and narrow air blowing end, and the long and narrow blowing end is formed with a long and narrow air blowing port with an opening inclined upward, so as to spray air jets in the direction of the rear panel of the operation cabinet or vertically upward; and A first air supply space is formed between the left end of the long and narrow air blowing end and the left side plate, a second air supply space is formed between the right end of the long and narrow air blowing end and the right side plate, and the long and narrow air blowing port is parallel to the long and narrow air suction port, When the air extraction device is in operation, an almost two-dimensional oblique air curtain is formed between the narrow and long air suction end and the long and narrow air blowing end. the

The exhaust device provided with deflecting plates in the present invention may also include an operation cabinet, front and rear left deflecting plates and front and rear right deflecting plates. Among them, the operation cabinet includes a suction hood, a bottom plate, a left side plate and a right side plate, and the frame surrounds it to form an accommodating space. Openings are formed at the front and rear of the operation cabinet respectively. The air end is formed with a narrow and long air suction port with the opening facing downwards. The long and narrow air suction port is perpendicular to the left and right side plates, and the air suction end is connected to the air extraction device to draw air upwards; The side plates are erected and fixed in the accommodating space in a deflected manner, so that a first angle is formed between the front and rear left deflectors and the left side respectively; and the front right deflector and the front left deflector Symmetrical, the rear right deflecting plate and the rear left deflecting plate are left and right symmetrical, and the front and rear right deflecting plates are respectively erected and fixed in the accommodating space in a deflected manner relative to the right side plate, so that the front and rear right deflection A second included angle is formed between the folding plate and the right side plate respectively. the

An operation cabinet includes an air suction hood, a bottom plate, a left side plate and a right side plate, and the frame surrounds it to form an accommodating space. The front and rear of the operation cabinet respectively form an opening, and the bottom of the air suction hood An air suction end is provided, and the air suction end is formed with a long and narrow air suction port with the opening facing downwards. device;

The front and rear left deflecting plates are respectively erected and fixed in the accommodating space in a deflected manner relative to the left side plate, and a first angle is formed between the front and rear left deflecting plates and the left side plate respectively; and

The front and rear right deflectors, the front right deflector and the front left deflector are bilaterally symmetrical, the rear right deflector and the rear left left deflector are bilaterally symmetrical, and the front and rear right deflectors are respectively relative to the right The side panels are erected and fixed in the accommodating space in a deflected manner, and a second included angle is formed between the front and rear right deflecting panels and the right panel respectively. the

Beneficial technical effect of the present invention:

1. The left and right deflectors of the present invention can not only guide the air to replenish air, prevent the air entering the operation cabinet from flowing back, but also effectively guide the air flow in the operation cabinet, so that pollutants can be removed Effective removal to reduce the leakage of pollutants;

2. The first deflector, the second deflector, the first guide part and the second guide part of the present invention can guide the air smoothly, so as to reduce the large backflow generated when the air is sucked into the opening, so Firstly, it can effectively prevent backflow from bringing oil fumes or pollutants out from the opening. the

For the convenience of a deeper understanding of the present invention, it is described in detail below:

Description of drawings

Fig. 1: is the front sectional schematic view of the first embodiment of the present invention. the

FIG. 2 is a schematic side sectional view of the first embodiment of the present invention. the

FIG. 3 : is a top cross-sectional schematic view of the first embodiment of the present invention. the

3A, 3B: are schematic cross-sectional views of another shape of the suction hood of the present invention. the

Figures 4 and 5 are diagrams of the usage state of the first embodiment of the present invention. the

FIG. 6 is a schematic side sectional view of the second embodiment of the present invention. the

Fig. 6A: It is a schematic side sectional view of the present invention when a movable cabinet door is provided. the

FIG. 7 : is a top cross-sectional schematic view of the second embodiment of the present invention. the

Figures 8 to 10 are diagrams of the usage state of the second embodiment of the present invention. the

Fig. 11 is a diagram of the use status of the third embodiment of the present invention. the

Fig. 11A is a schematic side sectional view of the movable cabinet door of the present invention with an air blowing device installed at the bottom. the

FIG. 12 is a top cross-sectional schematic view of the fourth embodiment of the present invention. the

Figure 13: It is a front sectional schematic diagram of a conventional air curtain type exhaust cabinet. the

Figure 14: It is a schematic side sectional view of a conventional air curtain type exhaust cabinet. the

【Description of main component symbols】

Exhaust device with deflection plate 1 Operation cabinet 2 Suction hood 21

Suction end 211 Suction port 212 Exhaust port 213

Air collection box 214 Air extraction device 215 Bottom plate 216

Liquid blocking frame 217 Liquid collection box 218 Bottom plate 22

Air blowing end 221 First air supply space 222 Second air supply space 223

Blowing port 224 Blower 225 Second guide part 226

Left side board 23 First deflector board 231 Right side board 24

The second deflector 241 front plate 25 openings 251, 254

First guide part 252 Air blowing device 253 Movable cabinet door 255

Rear panel 26 Storage space 27 Locker 29

Left deflector 3 First included angle θ1 Front and rear left deflectors 31, 32

Right deflector 4 Second included angle θ2 Front and rear right deflector 41, 42

Air curtain 8 Heating equipment 9 Operation cabinet a

Blowing end b, b1 Suction hood c Suction end c1

Air curtain d, d1 Left and right side panels e, e1 Clearance f, f1

Detailed ways

As shown in FIGS. 1-3 , it is a first embodiment of an exhaust device 1 with a deflector plate according to the present invention, which includes an operation cabinet 2 , a left deflector plate 3 and a right deflector plate 4 . the

The operating cabinet 2 is roughly in the shape of a cuboid, and a locker 29 with legs is provided below it to support the operating cabinet 2 upwards and store objects. The operating cabinet 2 includes a suction hood 21, a bottom plate 22, and a left side plate 23. A right side panel 24 and a rear panel 26. After the panels are combined, an accommodating space 27 is formed inside the operation cabinet 2, and an opening 251 is formed under the front end of the suction hood 21. And the bottom of the front end of the suction hood 21 is provided with an arc-shaped first guide portion 252, and the top of the front end of the base plate 22 is provided with an arc-shaped second guide portion 226, and the left side plate 23 in the operation cabinet 2 The front end and the front end of the right side plate 24 are respectively provided with an arc-shaped first deflector 231 and an arc-shaped second deflector 241 to reduce the degree of vortex and disturbance when the air is sucked into the opening 251 . During implementation, the first guide part 252, the second guide part 226, the first deflector 231 and the second deflector 241 can be in the shape of a 1/4 arc with a large radius, or can be in the shape of a large radius of curvature. The curved surface can also achieve the effect of guiding air. the

The bottom of this suction hood 21 is provided with an air extraction end 211, and this air extraction end 211 forms an air extraction port 212 with an opening facing downwards. The rear plate 26 is parallel. The top of the suction hood 21 is provided with several exhaust ports 213, and each exhaust port 213 is respectively connected to a wind collection box 214, and the wind collection box 214 is connected to an air extraction device 215, so that when the air extraction device 215 is running, the long and narrow The air suction end 211 draws air and guides the air in the operation cabinet 2 upward. During implementation, the air extractor 215 is an exhaust fan, blower or other fluid machines capable of extracting air. In addition, a liquid blocking frame 217 is provided on the bottom plate 216 of the suction hood 21 . The liquid blocking frame 217 protrudes upward from the bottom plate 216 and surrounds the narrow air suction port 212 . A liquid collecting box 218 is arranged below the rear end of the bottom plate 216 of the suction hood 21 , and the liquid collecting box 218 can also be arranged under the front end or side of the bottom plate 216 . the

During implementation, the suction hood 21 can also be a slightly L-shaped shell, and as shown in FIG. Towards a direction away from the back plate 26 . the

The left and right deflecting plates (3, 4) are respectively a rectangular vertical plate, wherein the left deflecting plate 3 is erected and fixed in the accommodating space 27 in a deflected manner relative to the left side plate 23, and the left deflecting plate 3 The front end of the deflection plate 3 is close to the right side of the left side plate 23, so that a first angle θ1 is formed between the left deflection plate 3 and the left side plate 23, and the angle opening of the first angle θ1 faces rear plate 26. The right deflector 4 is left-right symmetrical to the left deflector 3, and the right deflector 4 is erected and fixed in the accommodating space 27 in a deflected manner relative to the right side plate 24, and the front end of the right deflector 4 Close to the left side of the right side plate 24 , so that a second angle θ2 is formed between the right deflecting plate 4 and the right side plate 24 , and the opening of the second angle θ2 faces the rear plate 26 . the

In this way, as shown in Figures 4 and 5, when the object or facility on the worktable 22 is a heating device 9 that can generate high-temperature oily fume, such as a heating furnace or a heating plate, the high-temperature oily fume is acted on by the buoyancy of the high-temperature gas, that is, Allows the fumes to rise. When the air extraction device 215 is in operation, oil fume is sucked upward through the air extraction port 212, and the external air in front of the operation cabinet 2 is allowed to pass through the opening 251 below the front end of the air suction hood 21 to replenish air, and the left deflection plate 3 and the right deflection plate are used to supply air. The folded plate 4 is used to guide the air flow to form a pair of stable vortexes close to each other as shown in FIG. 4 , so as to stably bring the oil fume to the upper air inlet 212 and discharge it outward. Wherein, when the airflow flows on the right side of the left side plate 23 and the left side of the right side plate 24 of the operation cabinet 2, due to the obstruction and guidance of the left and right deflector plates (3, 4), the airflow can be allowed to enter the operation cabinet. The air in the cabinet 2 will no longer flow back along the entry path of the original opening 251, and high-temperature oily fume can be prevented from leaking outward. the

As shown in Figures 6 and 7, it is the second embodiment of the exhaust device 1 with a deflecting plate according to the present invention, which is different from the first embodiment in that: a front plate 25 is further provided under the front end of the operation cabinet 2 , the opening 251 is formed at the bottom of the front panel 25 , and the first guiding portion 252 is a semicircular horizontal bar formed at the inner side of the bottom of the front panel 25 . During implementation, also as shown in Figure 6A, the outer part of the front plate 25 overlaps a movable cabinet door 255, and the first guide portion 252 is formed on the bottom inner side of the movable cabinet door 255, and the movable cabinet door 255 can slide freely up and down with respect to front plate 25, to control the opening degree of movable cabinet door 255. In addition, the front side of the bottom plate 22 of the operation cabinet 2 is provided with a long and narrow air blowing end 221, a first air supply space 222 is formed between the left end of the long and narrow air blowing end 221 and the left side plate 23, and the long and narrow air blowing end A second air supply space 223 is formed between the right end of 221 and the right side plate 24 , and the elongated air blowing end 221 forms a elongated air blowing port 224 parallel to the elongated air suction port 212 . In addition, the long and narrow blowing end 221 communicates with a blower 225 so that the blower 224 can vertically blow out a two-dimensional air jet through the blower 225 . During implementation, the air blowing port 224 can also blow out a two-dimensional air jet in the direction of the rear panel 26 of the operation cabinet 2; the blower 225 can also be replaced by a cross-flow fan or other fluid machinery. the

Thereby, as shown in Figures 8-10, when the air extraction device 215 and the blower 225 operate synchronously, the air jet flow is ejected upwards from the air blowing port 224, and the air jet flow is sucked in by the air suction port 212, allowing the air to pass through the first supplementary air. The space 222 and the second air supply space 223 are used to replenish air, and when the left deflector 3 and the right deflector 4 are used to guide the airflow, the narrow and long air blowing port 224 and the narrow and long air suction port 212 can be formed. An almost two-dimensional oblique air curtain 8 will bring the pollutants surrounded by the oblique air curtain 8, the rear panel 26 of the operation cabinet 2 and the left and right side panels (23, 24) to the upper side with airflow stably. In the suction hood, it is discharged outside through the wind collecting box 214. the

As shown in Figure 11, it is the third embodiment of the exhaust device 1 with the deflector plate of the present invention, wherein, the bottom of the front plate 25 is provided with a strip-shaped air blowing device 253, to blow air downwards , so as to prevent high-temperature oil fume or other pollutants from leaking out. During implementation, the air blowing device 253 can also be set as two, and they are respectively arranged at both ends of the bottom of the front plate 25 . And as shown in FIG. 11A , when the outer part of the front panel 25 overlaps a movable cabinet door 255 , the air blowing device 253 is arranged at the bottom of the movable cabinet door 255 . the

In addition, FIG. 12 is a fourth embodiment of the exhaust device 1 with a deflection plate according to the present invention, wherein an opening (251, 254) is formed at the front and rear of the operation cabinet 2, that is, the front and rear of the operation cabinet 2 Through, the accommodating space 27 is provided with front and rear left deflecting plates (31, 32) inclined relative to the left side plate 23 and front and rear right deflecting plates (41) inclined relative to the right side plate 24. , 42), the front and rear left deflectors (31, 32) form a first included angle θ1 with the left side plate 23 respectively, and the front and rear right deflectors (41, 42) are respectively connected to the right side A second included angle θ2 is formed between the plates, and the front right deflecting plate 41 and the front left deflecting plate 31 are bilaterally symmetrical, and the rear right deflecting plate 42 is bilaterally symmetrical to the rear left deflecting plate 32 . Thereby, high-temperature cooking fumes or other pollutants can be prevented from leaking outward from the front or rear of the operation cabinet 2 , and users can conduct experiments or cook at the front or rear of the operation cabinet 2 at the same time. the

Therefore, compared with traditional exhaust cabinets and air curtain type exhaust cabinets, the present invention has the following advantages:

1. The left and right deflectors of the present invention can not only guide the air to replenish air, prevent the air entering the operation cabinet from flowing back, but also effectively guide the air flow in the operation cabinet, so that pollutants can be removed Effective removal to reduce the leakage of pollutants. the

2. The first deflector, the second deflector, the first guide part and the second guide part of the present invention can guide the air smoothly, so as to reduce the large backflow generated when the air is sucked into the opening, so Firstly, it can effectively prevent backflow from bringing oil fumes or pollutants out from the opening. the

To sum up, according to the content disclosed above, the present invention can clearly achieve the expected purpose of the invention, and provide an exhaust device with a deflection plate that can effectively reduce the dissipation of pollutants and ensure safe use. practical value,

But the above are only preferred embodiments of the present invention, and should not limit the implementation scope of the present invention; therefore, all simple equivalent changes and modifications made according to the patent scope of the present invention and the content of the description of the invention, All should still belong to the scope that the patent of the present invention covers. the

Claims (7)

1. an exhaust apparatus with deviation plate, is characterized in that comprising:

An operation cabinet, comprise plate after an air-suction cover, base plate, left plate, right plate and, and frame encloses an accommodation space of formation, the place ahead of this operation cabinet forms an opening, the bottom of this air-suction cover is provided with the end of bleeding, this end of bleeding is formed with a downward opening thin-and-long bleeding point, and this thin-and-long bleeding point is parallel with rear plate, and this end of bleeding connects an air extractor that confession is upwards bled;

A left avertence flap, is uprightly fixed in accommodation space in the mode with respect to left plate deflection, forms first angle between left avertence flap and left plate; And

A right avertence flap, is symmetrical in left avertence flap, and this right avertence flap is uprightly fixed in accommodation space in the mode with respect to right plate deflection, forms second angle between right avertence flap and right plate;

Wherein the front end of this left avertence flap abuts against on the right flank of left plate, and the front end of this right avertence flap abuts against on the left surface of right plate, and the angle opening of the first angle and the second angle is towards rear plate.

2. the exhaust apparatus with deviation plate according to claim 1, is characterized in that: the bottom of the front end of this air-suction cover is provided with the first guidance part of an arc, and the top of the front end of this base plate is provided with the second guidance part of an arc.

3. the exhaust apparatus with deviation plate according to claim 1, is characterized in that: the place ahead of this operation cabinet is more provided with a header board, and this opening is formed at the below of header board.

4. the exhaust apparatus with deviation plate according to claim 3, is characterized in that: the bottom of this header board is provided with a microscler blowning installation that feeds to lower air blowing.

5. the exhaust apparatus with deviation plate according to claim 1, is characterized in that: the front side of this base plate is provided with a thin-and-long air blowing end, and this thin-and-long is blown to hold and is formed with an opening up thin-and-long inflatable mouth; Between the left end of this thin-and-long air blowing end and left plate, form a first tonifying Qi space, between the right-hand member of this thin-and-long air blowing end and right plate, form a second tonifying Qi space, and this thin-and-long inflatable mouth is parallel with thin-and-long bleeding point, with when air extractor turns round, thin-and-long is bled and between end and thin-and-long air blowing end, form an oblique gas curtain.

6. the exhaust apparatus with deviation plate according to claim 1, it is characterized in that: the front end of the left plate of this operation cabinet is provided with the first deflector of an arc, the front end of the right plate of this operation cabinet is provided with the second deflector of an arc, and this first deflector and this second deflector enter in accommodation space for air-guiding.

7. an exhaust apparatus with deviation plate, is characterized in that comprising:

An operation cabinet, comprise an air-suction cover, a base plate, a left plate and a right plate, and frame encloses an accommodation space of formation, the place ahead of this operation cabinet and rear form respectively an opening, the bottom of this air-suction cover is provided with the end of bleeding, this end of bleeding is formed with a downward opening thin-and-long bleeding point, and this thin-and-long bleeding point is vertical with left and right side plate, and this end of bleeding connects an air extractor that confession is upwards bled;

Forward and backward left avertence flap, is uprightly fixed in accommodation space in the mode with respect to left plate deflection respectively, and forward and backward left avertence flap respectively and between left plate, form first angle; And

Forward and backward right avertence flap, front right deviation plate and front left deviation plate are symmetrical, rear right deviation plate and rear left deviation plate are symmetrical, and this forward and backward right avertence flap is uprightly fixed in accommodation space in the mode with respect to right plate deflection respectively, forward and backward right avertence flap respectively and between right plate, form second angle;

Wherein the front end of this left avertence flap abuts against on the right flank of left plate, and the front end of this right avertence flap abuts against on the left surface of right plate, and the angle opening direction of the first angle and the second angle is towards this accommodation space inner side.